API 5CT standard (American Petroleum Institute Casing and Tubing Specification) is the globally accepted seamless steel pipe technical standard in the oil and gas industry. Its core characteristics include high crush strength, corrosion resistance, and good weldability. This type of steel pipe is widely used in oil and gas well casing, tubing, and deep well drilling. For example, in the Changqing Oilfield shale oil horizontal wells, API 5CT standard P110 grade seamless casing...